Having completed the genomes of Loa loa, W. bancrofti, and O.volvulus, we have utilized the genomic data as the backdrop for performing a large number of proteomic studies. We have completed a large-scale proteomic characterization of almost all the major mammalian stages of Brugia malayi, resulting in the identification of more than 62% of the products predicted from the Brugia malayi draft genome. The analysis also yielded much of the proteome of Wolbachia, the obligate endosymbiont of Bm. Of the 11,610 predicted Bm gene products, 7,103 were definitively identified from adult male, adult female, blood-borne and uterine microfilariae, and infective L3 larvae. . Parasite sex- and stage-specific protein expression identified those pathways related to parasite differentiation and demonstrated stage-specific expression by the Bm endosymbiont Wolbachia as well. To understand better the developmental programs that underscore the transition between the mosquito-derived infective stage larvae (L3) to mammalian adapted L3s and to L4s following a molt, and the initial week of adaptation to the human host, we adapted an in vitro system that allowed for L3 development and subsequent molting to the L4. Using microarray and proteomic assessments at multiple times through this 9 day process we have not only identified those genes/pathways that are critical for the L3/L4 transition but we have also demonstrated by both pharmacologic inhibition (cysteine protease inhibition) and RNAi (of the critical CPLs) the critical role played by cysteine proteases in the early development of mammalian adapted L3s to L4s. We have recently performed shotgun mass spectroscopy on both human sera of patients with defined filarial infections, excretory/secretory (E/S) products of Loa loa microfilariae, all stages of the O. vovlulus worm, and appropriate controls to identify parasite derived biomarkers of active infection. This has led to identification of molecular targets that will be used to configure quantitative immunoassays for the rapid detection of active infection for O. volvulus and Loa loa. In that S stercoralis is a major pathogen in both normal and immunocompromised hosts, and very little is known, at the molecular level, about its makeup. We were able to manufacture microarrays comprising all 3571 clusters from first and infective third stage larvae (L1, L3i). We have since performed two important set of analyses, the first comparing L1 to L3i that identified the major transcriptional differences between infective and noninfective S. stercoralis larvae 29 that identified potential therapeutic and vaccine targets that were then tested experimentally 30. The second set of gene expression studies compared infective third stage larvae before (L3i) and 72 hours after (L3+) host invasion and showed that S. stercoralis larvae markedly downregulate expression of extracellular matrix and energy metabolism genes, and increase expression of genes encoding catalytic enzymes providing important clues toward an understanding of how Ss establishes itself following host invasion. From a pool of over 1,800 L. loa microfilaria (mf) expressed sequence tags, 18 candidate L. loa (Ll) mf-specific PCR targets were identified. Real-time PCR (qPCR) assays were developed for two targets (LLMF72 and LLMF269) and these have been used in the quantitative assessment of Loa loa microfilarial levels using both standard and isothermal methods.